The present invention relates to a machine for shaping or faceting workpieces such as gemstones. The machine may also be used for shaping industrial diamonds and metals such as carbide steel for cutting tools.
Grains in diamonds are unpredictable and locating them is time-consuming. Cutting and polishing in the direction of the grains are impossible, making the faceting of a plurality of diamonds, in one and the same operation, nonachievable for diamonds, in the prior art. Additionally, diamonds are attached to holders usually through a press-pot or some other mechanical system and if glued, the diamonds tend to shift position in the holder on account of the heat generated during the cutting and polishing steps or, they detach themselves altogether from the holders. Diamonds are generally cut and polished manually and in recent years with a robotic machine. However, even with the robotic machine, the diamonds are always cut and polished one at a time.
A variety of machines for faceting and otherwise processing gemstones are known in the art. One such early machine is shown in U.S. Pat. No. 515,595 to Linden. The Linden patent relates to a work-holder for grinding machines used to grind articles such as precious stones. The work-holder for holding the precious stones on the abrading face of a lap or other grinding stone has a series of shafts adapted to be turned in unison, and drops carrying the stones are connected by universal joints with the shafts. A gear system is used to rotate the shafts.
U.S. Pat. No. 3,404,491 to Emain relates to a gem working machine having a plurality of parallel stone-carrying spindles mounted on a frame. One end of each spindle carries a stone to be worked, while the other end is rotated by a driving mechanism.
U.S. Pat. No. 3,940,888 to Wain illustrates a faceting device for gemstones. The device orients a gemstone for forming facets thereon in a plurality of coaxial rows with equal spacing of the facets in the rows. A dop stick is provided on the end of a faceting shaft secured in a quill sleeve rotatably mounted in a faceting head which can be angularly adjusted for different facet rows to be formed. A spring-biased detent trigger is pivoted on the bracket to engage between the teeth of an indexing gear secured on a collar on the quill sleeve near the other end of the shaft. A positioning pin is secured to the collar and projects through the gear. A guide disc having evenly spaced peripheral notches is engaged around and can be rotated on a flange bushing threadably engaged on the quill sleeve adjacent the gear. A coil spring is provided on the bushing for urging the disc toward the gear. The disc has respective holes spaced to receive the pin to establish the angular relationship between the successive rows of evenly spaced facets. The notches on the guide disc move the detent trigger into engagement between the gear teeth for assuring uniform angular rotational steps of the shaft in forming the facets of a particular row.
U.S. Pat. No. 4,603,512 to Cave et al. relates to an apparatus for lapping a facet at the tip of a stylus by softly setting the tip down adjacent a rotating scaife which comprises a movable carriage supported on a platform by a means for translating the carriage along a first horizontal axis. The carriage is moved vertically along a second axis substantially orthogonal to the first axis. A stylus holder in the form of a turret operates to pivot the stylus toward the scaife and is biased by a spring or weight to assure a soft set down of the stylus tip on the scaife. A displacement sensor senses the angular displacement of the holder and generates a displacement signal proportional to the angular displacement relative to a predetermined reference position.
U.S. Pat. No. 4,715,148 to Landgraf relates to yet another gem faceting machine. The Landgraf machine has a main working spindle which can be pivoted in a vertical plane to obtain various inclinations of its axes. The spindle is amenable to height adjustment and is capable of being rotated about its own axis. There is also provided a means for latching the rotational position of the spindle in particular positions as well as in positions in-between the particular positions. The machine has a multiple gem mounting structure which includes a multiple chuck mounting element connected to the spindles for being turned therewith. The mounting structure also has a plurality of bores containing sleeves which in turn receive pin receiving spindles serving as rotatable chucks. It also includes a rotatable and position arrestable actuating element. A cover having a circle of latch bores is provided and a central drive element is coupled for rotation to the pin receiving spindles by means of gear pairs. An indexing pin holds the cover in one of the positions defined by the bores. A plurality of gem mounting pins are directly or, through an adapter element, indirectly mounted to the spindles. For latching the main spindle, one either uses existing latch equipment or integrates the same with the chuck mounting element.
U.S. Pat. No. 3,811,229 to Montgomery also relates to a gem faceter. The Montgomery faceter comprising a pivot block which is vertically movable to various positions. A pivot arm is pivotally mounted at one end to the pivot block. A head is mounted to the other end of the pivot arm and is adapted for movement to various positions about a pivot pin. A dop is mounted in the head and adapted to be rotated about its axis to various positions. An index plate is fixedly mounted on the dop. The index plate has markings thereon which indicate the number and position of desired facets to be ground on a gem held by the dop. An index plate clamp for locking the index plate successively in the desired marked positions relative to the head for grinding the facets is provided.
A lapping table is adapted to be contacted by the dopped gem. A protractor is provided for continuously indicating the angular position of the dop relative to the vertical. An adjustment stop is provided for limiting the movement of the head toward the lapping table. A sensor is mounted on the stop for sensing the degree of movement of the head toward the lapping table. An electronic circuit for translating the degree of movement sensed by the sensor into an electronic signal and a visual indicator for indicating the value of the electronic signal and the degree of the movement are provided so that the faceting angle may be detected and duplicated with a degree of precision.
U.S. Pat. No. 1,575,156 to Ecaubert relates to a machine for grinding and polishing gemstones. The Ecaubert machine has a revolvable lap member together with a revolvable drum or work carrying member adapted to revolve in an opposite direction. The machine is constructed so that the revolvable work member oscillates over the lap member in order to bring the surface of the article to be ground successively into contact with all portions of the grinding surface of the lap member. The oscillating movement is controlled so as to cause a substantially even wear on the entire surface of the lap member.
Despite the existence of these machines for faceting and otherwise processing gemstones, there still remains a need for a machine that is capable of faceting a great volume of workpieces in a relatively small area while having automatic cooling, moisturizing, and working material supply system. One of the problems with prior art machines is the extensive use of gearing arrangements which increased the space occupied by the machine and which prevented workpiece holding tools from being operated in unison. Such machines are only capable of faceting only fifteen stones at a time, because gear technology machines work in a linear formation and extend no more than ten inches. The gears also tend to malfunction quite often because they do not transmit well. In addition, the machines are not automated in terms of cooling, moisturizing and supplying material. Therefore, a factory machine is needed which is substantially automated, increases productivity and is less costly to operate.